Cargo bag with integral lifting loops

ABSTRACT

Four pairs of lifting panels extend upwardly from and have their lower end portions formed integrally with the upper edges of the side walls of the cargo bag. Each of the four pairs of lifting panels includes a pair of adjacent lifting panels positioned adjacent a corresponding corner of the cargo bag and the upper end portions of the lifting panels are folded inwardly to form multi-plies thereof. The multi-ply upper end portions of adjacent lifting panels are positioned in overlapping relationship and are interconnected to form a lifting loop above each corner of the cargo bag for supporting and moving the cargo bag from one location to another.

FIELD OF THE INVENTION

This invention relates generally to a cargo bag of flexible material for transportation and storage of bulk material and more particularly to such a cargo bag which includes a lifting loop adjacent each of the four corners of the bag. Each of the lifting loops is formed by joining together the upper end portions of a pair of lifting panels having their lower end portions formed integrally with and extending upwardly from the upper edges of the side walls and adjacent each corner of the bag so as to distribute the lifting stress over wide areas of the side walls.

BACKGROUND OF THE INVENTION

It is generally known to pronot shown) is removed from the workpiece as more fully described hereinbelow.

Also situated within the bore of the housing 12 is a closure plate 56 which is retained therein by suitable means such as the threaded ring 58. The closure plate 56 includes a bore 60 through which the spindle 34 passes. The closure plate 56 is provided with inner and outer upwardly projecting walls, 62 and 64 respectively.

A further, radially projecting lip 66, is also provided and forms a stepped bore into which sleeve 68 is press fit. Sleeve 68 is thus fixed relative to closure plate 56, which in turn, is fixed relative to housing 12. Sleeve 68 receives spindle 34 and acts to journal the same for rotation within the housing.

Projecting walls 62 and 64 form a web-like circular structure. Received within the web-like structure formed by upwardly extending projections 62 and 64 of closure plate 56, is a ring 72 which includes a bearing receiving channel 74 (best seen by reference to FIG. 2). A similarly constructed ring 76 is located just under reversing gear 44 so as to trap a yoked ball bearing assembly 80 between it and the ring 72. The yoked bearing assembly includes a plurality of periodically spaced balls which ride within the channels of the rings 72 and 74.

It is to be understood by those skilled in the art that during axial movement of the tapping attachment 10 away from the workpiece so that withdrawal of the tap (not shown) from the workpiece will be accomplished, a thrust load is generated. This thrust load is absorbed by interaction of upper ring 76 with balls 82, lower ring 72 and closure plate 56.

Projecting wall 62 is substantially shorter than wall 64. Ring 72 is approximately the size of the distance between walls 62 and 64 so that a snug fit is achieved, thus guaranteeing that the ring 72 remains relatively stationary, and radial migration thereof is minimal.

Ring 76 is placed in close running relationship to the surface of wall 64, near the top thereof and extends inwardly over the top of wall 62. Ring 76 may rotate with the reverse drive mechanism 44. The close fit of ring 76 to wall 64 assures minimal radial migration thereof during rotation.

It is to be understood by those skilled in the art that the tapping attachment 10 is moved towards the workpiece during machining operations at a rate of speed slower than the desired rate of progress of the tap into the workpiece. Thus, the free axial float spindle 34 will proceed towards the workpiece at its own desired rate due to rotation thereof and interaction of the the tap (not shown) with the workpiece (not shown). The reverse rate of axial retraction of the tapping attachment 10 away from the workpiece (not shown) is programmed into the machining center to be identical to the rate of approach. If the reversed rate of rotation of spindle 34 were not slowed by the bevel gear arrangement described the spindle would race the ball 32 past spline 50 into a neutral mode of operation before complete withdrawal of the tap from the workpiece and cause the tapping attachment 10 to constantly shift into and out of reverse drive as the housing 12 continuously caught up to the spindle drive ball 32. This would cause unnecessary wear and tear on the tapping attachment 10 and is avoided by the arrangement described.

Shown in FIG. 2 is an alternative embodiment of the present invention which accomplishes the same result of the arrangement depicted in FIGS. 1 and 3, and wherein identical elements are identically numbered, and modified elements are prefixed with a one (1); e.g., bevel gear 24 becomes bevel gear 124.

The only difference between the tapping attachment 110 and 10 is the provision of a split planet gear 140 and modified bevel gears 120 and 152 in place of their counterparts 40, 20 and 52 in the FIG. 1 embodiment. The description of common elements and function are hereby incorporated by reference as though repeated fully.

Planet gear 140 is a split gear having a different number of gear teeth at its outboard side than it does at its inboard side. Planet 140 may be formed as an integral unit or be composed of two different gears joined as by brazing. Bevel gear 120 is configured to contact only the outboard part of planet gear 140 and bevel gear 152 is configured to contact only the inboard portion of beveled gear 140. Thus by proper selection of gear ratios, any desired rate of counter-rotation of reverse drive member 44 may be achieved relative to forward drive member 18.

From the foregoing, those skilled in the art will readily understand the nature of the invention and the manner in which the mechanisms operate both in direct and reverse drive. It is to be understood that the above described embodiment is merely illustrative of some of the many specific embodiments which the present invention can take. Clearly, numerous and varied other arrangements may readily be devised by those skilled in the art without departing from the spirit and scope of the invention and the above description is to be understood as illustrative rather than limiting. The full scope of the invention is considered to be set forth in the appended claims hereto and is limited only thereby. 

What is claimed is:
 1. A tapping attachment including:a housing; a forward drive member received within the housing and associatable with a source of rotational drive to cause rotation of the forward drive member relative to the housing at a first speed; a reverse drive member received within the housing for rotation relative thereto in a counterdirection to the direction of rotation of the forward drive member at a second speed, means for causing simultaneous counter-rotation of the forward and reverse drive members at said first and second speeds; a free axially floating tapping spindle associatable with the forward drive member to cause rotation of the spindle therewith at said first speed and associatable with the reverse drive member to cause counter-rotation of the spindle therewith relative to the forward drive member at said second speed, and said first speed being greater than said second speed.
 2. A tapping attachment including:a housing; a forward drive member received within the housing and associatable with a source of rotational drive to cause rotation of the forward drive member relative to the housing at a first speed; a reverse drive member received within the housing for rotation relative thereto in a counterdirection to the direction of rotation of the forward drive member at a second speed; means for causing simultaneous counter-rotation of the forward and reverse drive members at said first and second speeds, said means for causing simultaneous counter-rotation comprising:(1) a forward drive bevel gear having a first quantity of teeth associated with said forward drive member for rotation therewith; (2) a reverse drive bevel gear having a second quantity of teeth associated with said reverse drive member for rotation therewith; (3) a planet gear means for communicating said forward drive and reverse drive bevel gears for counter-rotation; a free axially floating tapping spindler associatable with the forward drive member to cause rotation of the spindle therewith at said first speed and associatable with the reverse drive member to cause counter-rotation of the spindle therewith relative to the forward drive member at said second speed; said first speed being greater than said second speed; and wherein said first quantity of teeth is less than said second quantity of teeth to cause said reverse drive member to rotate at a slower rate of speed than said forward drive member. 